A subsidiary of intellectual-property firm Vringo is suing Microsoft for allegedly infringing two of its patents, Vringo said today.

Wholly owned subsidiary firm I/P Engine filed the suit in the Southern District of New York.

I/P Engine is seeking a judgment from the court declaring that Microsoft did infringe its patents and requests the court to award past and future damages through royalties and "any form of recoverable economic injury."

The two patents relate to U.S. Patent No. 6,314,420 and U.S. Patent No. 6,775,664, which detail essentially the foundation framework to how a search engine works.

In August, Vringo sold 9.6 million shares for $31.2 million to buy more than 500 patents and patents pending from Nokia -- a partner of Microsoft's in the smartphone space -- which were then used to sue ZTE in a U.K. court. The patent portfolio was worth only about $22 million, making the deal worthwhile for Nokia, but ultimately in the long run even better for Vringo, which may be able to reap even greater rewards from the ongoing lawsuit. That is, if it wins.

It's not the first time the company -- or one of its subsidiaries -- has taken a technology behemoth to court. Late last year, Vringo sought hundreds of millions from Google, AOL, and others in regard, The Wall Street Journal notes, to the same two patents being cited in the Microsoft suit (The Journal also reports that the Microsoft suit targets the company's Bing search engine). The patent hoarder collected only a fraction of its total requested amount in damages.